Originally Posted by SanderO
A displacement hull does not plane...
Yeah they do, just not very well and for very short periods of time.
All multihulls displace water just like any other hull and plane when pushed harder than "displacement speed" just like any other hull. The thing is that the dynamics of the event start to alter as the beam to length ratio decreases (and the wetted surface area, weight etc etc alters). I have had it explained to me and it gets complicated, so I am not the one to explain, but my understanding is that the relationship or "multiplier" constantly alters... i.e. its a curve not a fixed ratio and it is far more efficient at the narrow beam end of the scale.
Try asking at www.boatdesign.net
there are plenty of designers there that will explain if you ask nicely.